package demo1;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import java.util.HashMap;

public class UdpDictServer {
    private DatagramSocket socket = null ;
    private HashMap<String , String> dict  = new HashMap<>();

    public UdpDictServer(int port) throws SocketException {
        this.socket = new DatagramSocket(port);
        this.dict.put("dog" , "小狗") ;
        this.dict.put("cat" , "小猫") ;
        this.dict.put("car" , "汽车") ;
        this.dict.put("pig" , "小猪") ;
    }
    public void start () throws IOException {
        System.out.println("服务器启动");
        while(true){
            DatagramPacket requestPacket = new DatagramPacket(new byte[4096] , 4096) ;
            socket.receive(requestPacket);
            String request = new String(requestPacket.getData() , 0 , requestPacket.getLength()) ;
            String response = process(request) ;
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes() , response.getBytes().length
            , requestPacket.getSocketAddress()
            ) ;
            socket.send(responsePacket);
            System.out.printf("[%s,%d]request= %s , response = %s \n" ,requestPacket.getAddress() , requestPacket.getPort(),
                     request , response
                    );
        }

    }

    private String process(String request) {
     return dict.getOrDefault(request , "该词在词典中不存在") ;
    }

    public static void main(String[] args) throws IOException {
        UdpDictServer server = new UdpDictServer(6060);
        server.start();
    }

}
